We stayed in Assos last June. Not in these apartments but the Sea Path apartments with Ionian Island Holidays which are nearby (and lovely). We saw the Apollonia - in a fabulous position, right on the little shingle beach. Assos is lovely, as long as you like quiet places - we do and loved it. A few coach trips call in the day but these are generally gone in about an hour and didn't spoil the place. There are a handful of tavernas, all good, a small harbour and shingle beach and a small mini-market. The road leads across the narrow neck of land becoming a dirt road heading onto the headland and up to the ruined castle.

Unless you like doing very little, I'd say car hire was essential to visit other parts of the island. Fiscardo is about half an hour's drive away and the famous Myrtos beach about a 20 minute drive. Most of the island is reachable for day trips by car. If you have any specific questions, please ask. Here are some photos from my visit to give you an idea.

http://www.worldisround.com/articles/331247/index.html

Thankyou MariaH
Your reply is a great help and those pictures are beautiful. I have passed the link to my friends.
One question I have is that one of my friends is a vegetarian, do you think he will be ok with the handful of tavernas?

Thanks

I don't think there would be any problem for vegetarians. Both our preferred tavernas, Platanos, in the village square and Nefeli, by the beach had quite extensive menus. I have a more detailed trip report on here, if you are interested:

http://www.zorbas.de/scripts/phpBB2/viewtopic.php?t=4194

I'd recommend an evening meal in Fiscardo too. Some (but not all) restaurants there were a bit more expensive but these also had more up-market menus.